1. Field of the Invention
The present invention relates to an image reading apparatus for reading an image of an irradiated object having a portion of reflecting and a portion of transmitting light as in a banknote or the like.
2. Description of the Related Art
In a background art, there is an image reading apparatus of this kind described in, for example, JP-A-2000-113269. That is, JP-A-2000-113269 describes a banknote examining apparatus for examining a banknote or the like by irradiating light to a watermark pattern of a banknote or the like, detecting light transmitted therethrough by an artificial retina chip, and processing information of a shape or the like and presence or absence of an watermark image by a knowledge processing circuit.
On the other hand, JP-A-2003-87564 describes an image reading apparatus using both of a so-to-speak transmitting type and reflecting type. Further, according to the image reading apparatus, there is described an image reading apparatus constituted such that a light source for a transmitting draft is contained in a draft cover, a draft mat is locked by the draft cover attachably thereto and detachably therefrom, whereas in reading a reflecting draft, the draft mat is mounted to the draft cover, in reading the transmitting draft, the draft mat is detached from the draft cover.
However, according to the banknote examining apparatus described in JP-A-2000-113269, there poses a problem that although a watermark portion of the banknote or the like can be examined, in order to examine a portion of reflecting light of the banknote or the like other than the watermark portion, the banknote or the like needs to pass the bank examining apparatus again.
Further, according to the image reading apparatus described in JP-A-2003-87564, although there is conceivable an apparatus using both of an image reading apparatus of a so-to-speak transmitting type (hereinafter, simply referred to as “transmitting type”) and an image reading apparatus of a reflecting type (hereinafter, simply referred to as “reflecting type”), in reading a reflecting portion of a draft and in reading a transmitting portion of the draft, there is needed troublesome time and labor of attaching and detaching the draft mat to and from the draft cover in accordance therewith to pose a problem that so far as the draft mat is attached thereto and detached therefrom, the meaning of combining the reflecting type and the transmitting type cannot sufficiently be achieved. Further, there is conceivable a case of simultaneously reading a reflecting portion and a transmitting portion of a draft by carrying a draft only once by installing a reflecting type and a transmitting type in parallel in a direction of carrying the draft. However, in this case, there poses a problem that the image reading apparatus per se is large-sized and is not efficient.